Rewrite Your DNA

If you don't like the health story your genes are telling, change it.

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You can’t choose your family—or the genes they passed down to you. But what if you could changehow your genes act? New research suggests we may have the ability to put”bad genes” on good behavior, reducing the risk for cancer and morefor ourselves, our kids, even our grandkids, all through everyday habits. Thispower comes courtesy of the epigenome, chemical tags that sit on top of andaround DNA. The epigenome controls when genes turn on or off and how loudlythey express your genetic programming. (If you’re blonde, how blonde?) And it’sproving much easier to manipulate than genes themselves, says Jean-Pierre Issa,M.D., a leukemia researcher at The University of Texas M.D. Anderson CancerCenter in Houston. Get ready to be the boss of your DNA.

What your folks did affects your health

DNA takes several generations to evolve, but some environmental conditions(chemical exposure, diet) can alter the epigenome and change how genes behave almost immediately. Case inpoint: In the ’70s, scientists saw that daughters of women who’d takendiethylstilbestrol (DES, a synthetic estrogen) during pregnancywere at high risk for a rare form of vaginal cancer and other reproductiveissues. Turns out, DES had damaged the daughters’ epigenomes in the womb, whichlater set about turning on cancergenes. Other studies also suggest that damaged epigenomes can be passeddown for generations from women and men. So while you may have healthy genes,what your parents or grandparents did before you were born could make yourgenes act otherwise.

You’re not doomed by your family history

Unlike damaged genes, unhealthy epigenomes can be repaired—in large part by you. Whatyou eat matters, although the jury is still out on which vitamins and otherfood components help keep healthy genes on track, and when and how you wouldneed them. If there’s one thing most epigenetic researchers seem to agree on,it’s that your overall lifestyle may have greater impact on your epigenome than any single nutrient. Dr. Issa and others suspect that certain habits such as smoking, drinking alcohol and taking megadoses of vitamins contribute to epigenetic alterations that accumulate over time, increasing your risk for cancer and other diseases. His best advice is short and sweet: “Exercise, avoid obesity and don’tsmoke.”

Cancer patients are already benefiting

What if we could treat cancer without chemotherapy, radiation and brutal side effects? That’s the aim of epigenetic therapies, which work to silence “bad” oncogenes—mutated genes that turn healthy cells cancerous—and activate “good” tumor-suppressor genes. “With epigenetic therapy, you don’t kill cells; you are trying to convince them to be good citizens again,” says Randy Jirtle, Ph.D., director of the Epigenetics and Imprinting Laboratory at Duke University in Durham, North Carolina. Four cancer drugs with epigenetic mechanisms are already on the market, and several clinical trials on epigenetic therapies are under way. While the science is still in its infancy, experts are hopeful. “Patients have fewer side effects,” Dr. Issa says, “and the treatments work.”

How the switch is flipped

Epigenetics is a complex science, no doubt. But Jirtle’s research on mice carrying a version of the agouti gene, which condemns the critters to obesity and yellow fur, instead of their usual sleek, brown physique, reveals how elegantly simple the chemistry can be.

TO B OR NOT TO B

Jirtle’s team fed one group of pregnant agouti mice a diet rich in B vitamins and other nutrients. A second group of genetically identical moms-to-be ateunsupplemented chow.

IT’S JUST AN EXPRESSION

A portion of the B vitamins attached in utero to specific points along the agouti gene—spots linked with fur color and metabolism. This process, called DNA methylation, changed the agouti gene’s expression of those traits.

DNA DENIED

Pups born to unsupplemented mice looked like Mom: fat and yellow. But those exposed to B vitamins were normal and brown. Nothing about their agouti gene had changed—only its epigenetic environment.